The present invention relates to luminescent coatings formed from hydrogen silsesquioxane resin and phosphor fillers. These coatings are useful on a variety of substrates.
The use of hydrogen silsesquioxane derived ceramic coatings on substrates such as electronic devices is known in the art. For instance, Haluska et al. in U.S. Pat. No. 4,756,977 disclose a process for forming a silica coating on an electronic substrate wherein a solution of hydrogen silsesquioxane resin is applied to a substrate followed by heating the coated substrate in air at a temperature in the range of 200.degree.-1000.degree. C. This reference, however, does not describe the use of fillers within the coating.
Similarly, the use of fillers within ceramic coatings is also known in the art. For instance, U. S. Pat. No. 3,986,997 describes a composition comprising an acidic dispersion of colloidal silica and hydroxylated silsesquioxane in an alcohol- water medium which can be used to apply transparent abrasion resistant coatings on a variety of substrates. The reference, however, does not describe the use of hydrogen silsesquioxane nor the application of a coating on an electronic substrate.
The present inventors have now discovered that luminescent coatings can be formed from compositions comprising hydrogen silsesquioxane resin and phosphor fillers.